The present invention relates to a tool for inserting and extracting pins of roller chains.
Tools of the above type are generally used for mounting a new chain on a bicycle or for varying the length of the chain, for example in the case in which the rear wheel of the bicycle is replaced with a wheel having a set of sprockets with a different number of teeth.
A chain tool of a known type is described in GB-B-912703. The described tool comprises a body which has a pair of teeth designed to engage the ends of two chain links that are to be connected or separated by inserting or extracting a pin. The body carries a screw member that can be operated manually and is provided with a punch, which, upon rotation of the screw member is forced into contact with one end of a pin that is to be inserted into the chain links engaged in the aforesaid teeth, or to be extracted from the said chain links.
A drawback of the chain tools according to the prior art lies in the fact that the user must manually hold the chain links in engagement with the teeth of the tool. This operation is very inconvenient in so far as the user must hold the tool with one hand, while with the other hand he acts on the screw member, which exerts the necessary pressure for inserting or extracting the pin. At the same time, with the hand that holds the tool, the user must press the chain links downwards, generally using a thumb. This operation proves inconvenient and does not afford any guarantee in terms of correct positioning of the chain links during insertion or extraction of the pin. In the case where insertion or extraction of the pin is carried out while the chain links are not properly positioned, there is the risk of damaging the holes of the links, with the consequent danger of weakening the chain and rendering it subject to failure due to stress.
With a view to overcoming the above-mentioned drawbacks, the subject of the present invention is a tool for removing and inserting a pin in elements of a roller chain.
A tool for removing and inserting a pin in aligned elements of a roller chain. The tool has a generally xe2x80x9cUxe2x80x9d shaped body; an element receiver having a base, opposed sides and an opening opposite the base that define a cavity to receive the elements of the roller chain and position them in alignment, with at least one of the opposed sides having defining therein an aperture positioned adjacent to the opening, the element receiver being located on a first branch of the xe2x80x9cUxe2x80x9d; a movable press punch located on a second branch of the xe2x80x9cUxe2x80x9d and positioned for powered movement toward the channel defined by the aligned elements; and a locking element that closes the receiver opening to retains the elements of the roller chain in the receiver cavity.